Intangible Assets and Goodwill (Schedule of Intangible Assets) (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Intangible assets, gross	$ 1,314	$ 1,312
Less: accumulated amortization	(597)	(583)
Intangible assets, net	717	729
Contractual arrangements
Finite-Lived Intangible Assets [Line Items]
Intangible assets, gross	923	921
Non-compete agreements
Finite-Lived Intangible Assets [Line Items]
Intangible assets, gross	14	14
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Intangible assets, gross	352	352
Trade names
Finite-Lived Intangible Assets [Line Items]
Intangible assets, gross	16	16
Technology
Finite-Lived Intangible Assets [Line Items]
Intangible assets, gross	$ 9	$ 9